Treatment of hydrocarbons



are generally e xliibitedlby' cn pq qas Patented Sept. 19, 1944 UNITEDSTATES PATENT OFFICE OF I IYDROCARBONS Herman S. Bloch, Chicago, 111.,assignor to Universal Oil Products Company, Chicago, 111., a

corporation of Delaware No Drawing. Application August 7, 1941,

' Serial No. 405,787

12 Claims. This iiivention relates to the treatment of hydrocarb ns ofessentially straight-chain structure, to increase their degree ofbranching and thus produce substantial yields of their isomericcounter-parts.

,The invention is more specifically directed to the isomerization ofnormal paraflin hydrocarbons beginning with normal butane as the onlygaseous representative of the class capable of isomerization andextending to the treatment of normally liquid normal paraflinhydrocarbons of considerably higher molecular weight although theprecise efiEect of the treatment to be hereinafter specified will varyconsiderably with the' molecular weight of the compounds or mixture ofcompounds treated. In one orits aspects the invention is directedparticularlyto the treat-' ment of parafilnic hydrocarbon fractionsproduced in the primary distillation of petroleum oils.

Generally speaking, the isomeric or branched chain paraflin hydrocarbonsare more reactive than the normal compounds and thus more cabons whichconsists in contacting them with metal halides of the Friedel-Craftstype, in the presence of hydrogen and hydrogen chloride, the amount ofhydrogen being gradually decreased during the period of operation andthe amount of hydrogen chloride being increased.

It is recognized that those skilled in the art of hydrocarbon conversionare already conversant with the use of catalysts of the Friedel-- Craftstype for the isomerization of hydrocarbons. Processes in present use,however, in conpable of entering into various types of hydrocarbonreactions particularly reactions of alkylation in which alkvl groups areadded to the molecules. In the case of normal butane, which occurs inrelatively large percentages in the gases produced incidental to theproduction of petroleum and its p mary distillation products and also inconnection with cracking processes, there are normally more butanes thanare required tofurnish gasolines of the usual 10 pound Reid v v vaporpressure so that numerous processeshave been developed to convert theexcess of butanes into gasoline boiling range materials and thus intrastto the process of the present invention, ordinarily employ approximatelyfixed ratios of hydrocarbon, hydrogen chloride and hydrogen and operateat a substantially uniform temperature in continuous processes. Incontrast to this, the present process starts out with relatively highproportions of hydrogen to hydrogen chloride and moderate temperaturesand maintains these conditions during a primary period of operation inwhich the catalyst has a relatively high activity. As the catalyticactivity decreases due to uncrease the overall yield ofgasolinegobtainable I alkylatable by normally gaseous olefinichydrocarbons including ethylene, propylene and the butylenesto producegood-yields of isomeric .par.-

from crude petroleum. 'Isobutane is readily which have antiknock valuescorrespond :1 C.-F. R. method. However, noprocesses have as yet beedeveloped to; a commercial-point which] permit the correspondingalkylation of normal butane so that one'practical aspector the presentinvention is immediately evident in that it ef-kg "tests the productionor isobutane tromthe'norv mal butane whichis presentin largeiduantitiesgIn the case-or the normallyiliquid :drocarbons-oi anti-knock value withdegree or branchingaotbatjthe highest antiknock tane numbers wellabove90 by the avoidable formation 01 metal halide complexes I-with"hydrocarb on by-products the. amount or hydrogen used is decreasedwhile the amount of hydrogen chloride is increased. Theeflect oidecreasing-thehydrogen is to compensate for the decreasing activity ofthe catalystcomposite in two ways. From the first standpoint, as thecat- :alystactivity decreases there will be a lessened tendencyiforundesirable side reactions other ,th'aiiii'son'ierization tooccur'sothat with/small oi-hydrogenin admixture with the hydrocarbonundergoing'treatment and assuming a constant rateiot introduction or thehydrocar--.hon teed there will be a longer time of contact with the catalys't;from the second standpoint, a larger-iamountoi hydrogen present in theearly stages] oi" the" processing .period- 'iessen the aamount .oi.'olefl nic hydrocarbons produced :due. to the cracking of the catalystcompgclte'l'so therejwlll be a small formation or halide-unsaturatedhydrocarbon complexes. An increase, in the amount of hydrogen chlorideas the hydrogen is decreased has always been found to exert acompensating influence in maintaining the activity of the metal halidecatpreferablyused in accordance with the present invention may includecombinations of anylof the known catalysts oi the Friedel-Craits typewhich have any definite activity in isomerizing alysts so that by bothdecreasing hydrogen and hydrocarbons and may also include correspondingincreasing hydrogen chloride there is a definite compounds of othermetals of lesser or substaniiezniiihejrriing oi the catalyst life sothat-it is utitially no activity such as, for example, compounds a e oronger periods of time without loss in of titanium, hafnium, thorium,columbium, thalactivity below a practical point. As one means lium, andthe metals of the alkaline earth and 0f y n t 811101111!- f y g p oyed,0 alkali metal groups. Low melting mixtures of it 1:111:11? be partiaglysubsttiltligted by inert gases such 'halides utilizable in the fluidcondition can be as rogen, me ane, e ne, or propane. formed by mixingproper proportions oi chlorides he imp oved features of op ration whichcharwhich are distinctly or the Friedel-Crafts type acterize the presentinvention are applicable to or by mixing a chloride of this type withanother digslryerit types or pirocelssgs iniswhich metal baggie chloridehaving substantially no activity in the ca 5 s are emp oye or omerizingpar n desired reaction. hydrocarbons. The simplest mode of operationWith regard to the conditions or temperature, which is applicable,particularly to the lower mopressure and flow which are optimum foreffectlecular weight normal paraflln hydrocarbons being any desiredisomerization according to the ig'rilnnligg with brgorniztll1buii'inarie l(:jbisists in 9 :1118 2o process of the iniagntgn, thecomginatidons will e rocar n e er q or vapor p ase evidently vary wi ecompoun un ergo r a r n l e l halide aly in d treatment and theparticular mode of operation beds under conditions selected for optimumconemployed so that only broad ranges can be given. version. Asavariation 01' this method the metal In general, temperatures of theorder of from halides either singly or in various mixtures may b ut 50to about 200 C. may be employed and d p i p 'elfl i y inert absorbent grnpressures from atmospheric to several hundred ular supports suchas, forexample, activated pounds per square inch. The temperature may carbons,iuller's earth, clays: of the bentonite' or be ai d adually during theprocessing period tm fll ni e p i r r r acid treated. to compensate forthe loss in catalytic activity. various refractory oxides such asprepared n at s willpbviousLv vary with the particui pp .ta. :..tatf;?.*f' 12 "i si aa tzzs if it o g a s e eera ya thecaracer cso es carsa with the metal halide. The third alternative Th feature of thpresent-invention consists method of operation may involve the use ormolin ing the amount or hydrogen employed ten metal halides orpreferably molten mixtures hi increasing the amount of hydrogen chloorlow fusing point through which the hydrocarride during the processingperiod, bong to be isomerized passed upwardly The following illustrativedata are introduced through a stationary pool. In all of these alter- 4to indicate the fl ct observed in lsomeflzing by. native processes thecatalystundergoes gradual dmcarbonsm accordance t t presentinvendeterioration and the process oi. the present in- 40 on althoughthe scope of the invention is not vention is particularly applicable tostabilize the to behmted in exact correspondence therewith g gg f overrelatively long An aromatic-free hexane cut from a parkafilric ber of 59e Catalysts of the Friedel-Crafts type include gfggi gg ggg fi g ggggfigfi granularyamr halides of such metals as aluminum, zirconium, 5 mmumchloride catalyst under a pressure of 500 zinc, tin, antimony, boron,etc., although it is um I poundsper square inch at a liq hour y spacerecognized that they are not interchangeable in 15 dr chloride hem addedany given type 01' reaction and that a11will not zg gfii i gz g 2: ogencatalyze certain reactions of the compounds The following tabulation ofdata shows the efmentioned, aluminum chloride is generally the fect ofadding hydrogen in the initial stages of a most applicable and zirconiumchloride and zinc th in him no chloride follow in approximate order ofdecreasrun as compared with ano er run W ing activity. The eutecticmixtures which are hy n w added- Prod weight ac e H01, peroen Bun B-moEshOO moles/00 Egg? i No. moles moles T C- H h2g1 mm cm 06H I C+.C.fraction on 1&3 64.7 87 $5 8,2 91.3 78.0 1:::::: 21 1 g g; 3 3; 1 28 i 14o Z 3 E g (an 1:::::: 49 o g g-g g; 3% 123: 33 3 53% 98 i 25 0 is 1000-6 Q3 33:1: g 3 i2 i3 3 3% M 2 a2 0 15 mo as -2 5331:: i3 3 i? g 3 2 n156 o 5 r 90.5 75.9

Lowapparentyieldsbecauseoi'grsdnaldisplacementciflainsystambyhexane.

From the above data it is seen that in the absence 'of initially addedhydrogen there is'a rapid decrease in the amount of isomerization as the1 run progresses and that in Run 1 wherein hydrogen was added arelatively constant conversion 1 was obtained during the initial periodof hydrogen addition and that the conversion and octane number-wasmaintained after the hydrogen feed had been discontinued.

- I claim as my invention: l. A process for the isomerization of aparafiin hydrocarbon to produce more highly branched isomers therefromwhich comprises contacting said hydrocarbon mixed with hydrogen and ahydrogen halide with a metal halide isomerizing catalyst of theFriedel-Crafts type for a period of duce more highly branched isomerstherefrom which comprises contacting said hydrocarbon mixed withhydrogen and hydrogen chloride with aluminum chloride for a period oftime corretime corresponding to a desired production of v said isomers,the amount oi. hydrogen mixed with said hydrocarbon being graduallyreduced and the amount of hydrogen halide mixed with said hydrocarbonbeing gradually increased during said period.

2. A process for the isomerization of a paraffin hydrocarbon to producemore highly branched isomers therefrom which comprises contacting saidhydrocarbon mixed with hydrogen and hydrogen chloride with a granularmass comprising a metal chloride isomerizing catalyst of the.

Friedel-Crafts type as its principal active constituent, tor a period oftime corresponding to a desired production or said isomers, the amountof hydrogen .mixed with said hydrocarbon being gradually reduced and theamount of hydrogen chloride mixed with said hydrocarbon being graduallyincreased during said period.

3. A process for the isomerization of a paraflln hydrocarbon to producemore highlybranched isomers therefrom which comprises contacting saidhydrocarbon mixed with hydrogen and a hy-. drogen halide with a fluidmass of metal halide isomerizing catalyst of the Friedel-Crafts type ashydrocarbon to produce more highly branched isomers therefrom whichcomprises contacting said hydrocarbon mixed with hydrogen and hydrogenchloride with a fluid mass of metal chloride isomerizing catalyst of theFriedel-Crafts type as its principalacti've constituent, for a period ortime corresponding to a desired production oi! said isomers, the amountof hydrogen mixed with said hydrocarbon being gradually re duced and theamount of hydrogen chloride mixed with said hydrocarbon being graduallyincreased during said period. r

5. A process for the isomerization of paraflln hydrocarbons ofstraight-chain structure to produce more highly branched isomerstherefrom which comprises contacting said hydrocarbon mixed withhydrogen and hydrogen chloride with a metal halide isomerizing catalystof the Friedelincreased during said sponding to a desired production ofsaid isomers. the amount 01' hydrogen mixed with said hydrocarbon beinggraduallyreduced and the amount of hydrogen chloride mixed with saidhydrocar bon being gradually increased during said period.

7. A process for converting parafllns into more highly branched isomerswhich comprises sublecting the vparailins under isomerizing conditionsto the action of a metal halide isoigerizing catalyst oi theFriedel-Crafts type in the presence of hydrogen and'a hydrogen halide,and, as the activity of the catalyst decreases and during the contactingtherewith of paraflins being isomerized, .reducing the proportion ofhydrogen and increasing the proportion 01' hydrogen halide with respectto the amount or paratfin undergoing treatment.

8. A process for converting parailins into more highly branched isomerswhich comprises subjecting the paraflins under isomerizing conditions tothe action of a metal halide isomerizing catalyst of the Friedel-Craftstype in the presence or hydrogen and a hydrogen halide, and reducing theratio of hydrogen to paraiiins and increasing the ratio of hydrogenhalide to parafilns as the activity oi the catalyst decreases during thecontacting of parafllns therewith.

9. A process for converting paraihns into more highly branched isomerswhich comprises adding hydrogen and a hydrogen halide to a stream of theparamns, contacting the resultant mixture under isomerizing conditionswith a metal halide isomerizing catalyst of the Friedel-Crafts type,and, as the activity of the catalyst decreases, reducing thehydrogen-paraflin ratio and increasing the hydrogen halidep'araflinratio in said stream. I

10. A process for converting parafllns into more highly branched isomerswhich comprises adding hydrogen and a hydrogen halide to a stream of theparaflins, contactingthe resultant mixture under isomerizing conditionswith a metal halid isomerizing catalyst of the Friedel-Craits type, and,as the activity of the catalyst decreases, re-

I ducing the amount or hydrogen and increasing the amount of hydr0genhalide added to said stream.

Crafts type for a period or time'corresponding 11. The process asdeflned in claim 8 further characterized in that said catalyst comprisesalu minum chloride and the hydrogen halide is hydrogen chloride.

12. The process as defined in claim Q'further' characterized in thatsaid catalyst comprises aluminum chloride and the hydrogen halide is hy-

